Fructose or lactose intolerance and malabsorption testing

June's issue of the Alimentary Pharmacology & Therapeutics examines the relationship between malabsorption testing with symptoms in functional gastrointestinal disorders.

The association of fructose and lactose intolerance and malabsorption with the symptoms of different functional gastrointestinal disorders (FGID) remains unclear.

Professor Wilder-Smith and colleagues from Switzerland investigated the prevalence of fructose and lactose intolerance, and malabsorption and their association with clinical gastrointestinal (GI) as well as non-GI symptoms in functional gastrointestinal disorders, and the outcome of dietary intervention.

Fructose and lactose intolerance, and malabsorption were determined in 1372 functional gastrointestinal disorders patients in a single center using breath testing.

The effectiveness of a targeted saccharide-reduced diet was assessed after 6–8 weeks.

Intolerance prevalence across all functional gastrointestinal disorders was 60% to fructose

Alimentary Pharmacology & Therapeutics

The team found that intolerance prevalence across all functional gastrointestinal disorders was 60% to fructose, 51% to lactose, and 33% to both.

Malabsorption occurred in 45%, 32% and 16% respectively.

The research team observed no differences in intolerance or malabsorption prevalence between functional gastrointestinal disorders subgroups.

Functional gastrointestinal disorder symptoms correlated with symptoms evoked during testing, but not with malabsorption.

The research team noted that non-GI symptoms occurred more commonly in patients with intolerances.

Methane breath levels were not associated with constipation using several cut-off thresholds.

The team found that adequate symptom relief was achieved in more than 80% of intolerant patients, irrespective of malabsorption.

Professor Wilder-Smith's team concludes, "Fructose and lactose intolerances are common in functional gastrointestinal disorders, and associated with increased non-GI symptoms, but not with specific functional gastrointestinal disorder subtypes."